Tornadoes · United States · Alabama · 2008

EF0 tornado, Collinsville, Alabama, May 20, 2008

Name: EF0 tornado, Collinsville, Alabama, May 20, 2008
Start: 2008-05-20T21:48:00.000Z
End: 2008-05-20T21:50:00.000Z
Location: Collinsville, Alabama

This EF0 tornado ran 0.2 miles across DeKalb County on May 20, 2008, touching down at 4:48 PM CDT and reaching 20 yards wide. It killed nobody, and did $1,000 of property damage.

The rating scale

Tracks are drawn in the color of the rating. The Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

EF065 to 85 mphthis tornado
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
EF2111 to 135 mph
Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.
EF3136 to 165 mph
Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
EF5over 200 mph
Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.
Unrated
The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

The record

Rating: EF0
Date: May 20, 2008
Touchdown: 4:48 PM CDT (21:48 UTC)
Lifted: 4:50 PM CDT (21:50 UTC)
On the ground: 2 minutes
Path length: 0.2 miles (0.3 km)
Path width: 20 yards (18 m)
Deaths: 0
Injuries: 0
Property damage: $1,000
County: DeKalb County
Touchdown point: 34.282, -85.878
Lift-off point: 34.282, -85.878
Record number: 0805201548-01

What the Weather Service recorded

A strong cold front pushed into a very unstable air mass which produced widespread wind damage, hail and an isolated weak tornado.

A brief, weak tornado touched down just west of county road 51, approximately 1/2 of a mile northeast of state highway 68. The tornado snapped large trees branches at a residence there, then tracked into a grassy field where convergent patterns were found. The tornado continued southeast for 1/4 of a mile. At the end of its path, it downed some trees after crossing nearby interstate 59.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

The warnings

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

Issued (UTC)	Expired	Product	Office
20:32 UTC	20:50 UTC	Severe Thunderstorm Warning	HUN
21:15 UTC	21:45 UTC	Severe Thunderstorm Warning	HUN
21:20 UTC	21:45 UTC	Severe Thunderstorm Warning	HUN
21:42 UTC	22:30 UTC	Severe Thunderstorm Warning	HUN
21:51 UTC	22:04 UTC	Tornado Warning	HUN

Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.

The forecast that day

The Storm Prediction Center had this point in a Slight Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 19:40 UTC.

SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.

The air that afternoon

The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.

Birmingham, AL (KBMX), 12:00Z

9.8 hours before the tornado, 148 km from the path. May 20, 2008.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.

Mixed-layer CAPE: 698 J/kg
Mixed-layer CIN: -197 J/kg
Surface CAPE: 283 J/kg
Mixed-layer LCL: 982 m above ground
0-6 km bulk shear: 40 kt
0-1 km bulk shear: 38 kt
0-1 km storm-relative helicity: 305 m²/s²
0-3 km storm-relative helicity: 356 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0
0-3 km lapse rate: 4.1 K/km

Open this sounding in Storm Lab

Birmingham, AL (KBMX), 00:00Z

2.2 hours after it, 148 km from the path. May 21, 2008.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.

Hodograph

Mixed-layer CAPE: 1707 J/kg
Mixed-layer CIN: -5 J/kg
Surface CAPE: 2486 J/kg
Mixed-layer LCL: 1475 m above ground
0-6 km bulk shear: 47 kt
0-1 km bulk shear: 17 kt
0-1 km storm-relative helicity: 130 m²/s²
0-3 km storm-relative helicity: 184 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 7.2
0-3 km lapse rate: 7.8 K/km

Open this sounding in Storm Lab

The radar

The Northeast Alabama radar (KHTX), 75 km away, was scanning. The volume nearest the touchdown began at 21:48 UTC.

Open the radar archive at this moment, over the track

Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.

What was reported nearby

Local storm reports within 60 km of the path, in the three hours either side.

Time (UTC)	Report	Where	County	Remark
20:45 UTC	HAIL 0.25	Sulpher Springs	Dekalb, AL	PEA SIZED HAIL FELL ALONG CR 739 NEAR SULPHUR SPRINGS
20:57 UTC	HAIL 0.5	4 Wsw Grant	Marshall, AL	DIME SIZED HAIL REPORTED NEAR GRANT
21:17 UTC	HAIL 0.88	Sylvania	Dekalb, AL	NICKEL SIZED HAIL REPORTED AT THE INTERSECTION OF ALABAMA HWY 75 AND CR 27 NEAR SYLVANIA
21:23 UTC	HAIL 1	2 S Henagar	Dekalb, AL	QUARTER SIZED HAIL REPORTED ALONG CR 85 NEAR HENAGAR
21:25 UTC	TSTM WND DMG	2 S Henagar	Dekalb, AL	TREES REPORTED DOWN ON CR 85 NEAR HENAGAR. ALSO QUARTER SIZED HAIL WAS STILL ONGOING.
21:28 UTC	TSTM WND DMG	3 W Geraldine	Dekalb, AL	A TREE WAS BLOWN DOWN IN THE WHITON AREA NEAR A CHURCH.
21:28 UTC	HAIL 0.5	2 S Valley Head	Dekalb, AL	DIME SIZED HAIL ALONG CR 89 JUST NORTH OF DESOTO STATE PARK
21:32 UTC	HAIL 1.75	Geraldine	Dekalb, AL	GOLFBALL SIZE HAIL WAS REPORTED AT THE GERALDINE ELEMENTARY SCHOOL.
21:35 UTC	TSTM WND DMG	1 Sw Geraldine	Dekalb, AL	POWER AND TELEPHONE LINES DOWNED ALONG AL HWY 75 JUST SOUTHWEST OF GERALDINE. TREES ALSO DOWNED AT THIS LOCATION.
21:35 UTC	TSTM WND DMG	2 W Geraldine	Dekalb, AL	POWER AND TELEPHONE LINES DOWNED ALONG AL HWY 75 JUST SOUTHWEST OF GERALDINE. TREES ALSO DOWNED AT THIS LOCATION.
21:36 UTC	TSTM WND DMG	1 Wsw Geraldine	Dekalb, AL	A LARGE PORTION OF A CHICKEN HOUSE NEAR THE INTERSECTION OF COUNTY ROADS 28 AND 391 WAS FLATTENED TO THE GROUND. ALSO A TREE WAS SNAPPED IN THE SAME AREA AND LARGE BRANCES WERE TORN FROM TREES. WINDS EXTIMATED AT 80 MPH.
21:37 UTC	TSTM WND DMG	2 Sw Geraldine	Dekalb, AL	ROOF PEELED UP IN LOCATIONS ON A MOBILE HOME ON COUNTY ROAD 28. WINDS ESTIMATED AT 70 MPH.
21:45 UTC	TSTM WND DMG	4 Ene Crossville	Dekalb, AL	A SIGN WAS BLOWN AWAY AT A WILLIAMS SERVICE STATION IN THE DAWSON COMMUNITY.
21:45 UTC	TSTM WND DMG	4 Ene Crossville	Dekalb, AL	PIECES OF AN OLD BILLBOARD WERE BLOWN ONTO THE GROUND NEXT TO THE WILLIAMS SERVICE STATION IN THE DAWSON COMMUNITY.
21:45 UTC	HAIL 1.25	Skirum	Dekalb, AL	HALF DOLLAR SIZED HAIL IN SKIRUM
21:48 UTC	TORNADO	1 Nw Collinsville	Dekalb, AL	A BRIEF...WEAK EF-O TORNADO TOUCHED DOWN JUST WEST OF COUNTY ROAD 51...APPROXIMATELY 1/2 OF A MILE NORTHEAST OF STATE HIGHWAY 68. THE TORNADO SNAPPED LARGE TREES BRANCHES AT A RESIDENCE THERE...THEN TRACKED INTO A GRASSY
21:50 UTC	TSTM WND DMG	Nw Collinsville	Dekalb, AL	A TREE WAS BLOWN DOWN ON AL HWY 68 AT THE BIG WILLS CREEK BRIDGE JUST WEST OF COLLINSVILLE.
21:50 UTC	HAIL 1	Collinsville	Dekalb, AL	QUARTER SIZED HAIL REPORTED BY THE COLLINSVILLE COOP OBSERVER.
21:52 UTC	TSTM WND DMG	1 Ne Collinsville	Dekalb, AL	TWO LARGE APPLE TREES UPROOTED APPROXIMATELY 1 MILE NORTH NORTHEAST OF COLLINSVILLE.
21:52 UTC	TSTM WND DMG	Se Collinsville	Dekalb, AL	VERY LARGE TREE BRANCHES FELL ON A HOUSE IN SOUTHEASTERN COLLINSVILLE. THIS CAUSED MINOR DAMAGE TO THE STRUCTURE.
21:55 UTC	TSTM WND DMG	2 Ese Collinsville	Dekalb, AL	A TREE WAS BLOWN DOWN ACROSS THE ROAD NEAR THE AL HWY 68 AND AL HWY 176 INTERSECTION.
22:00 UTC	HAIL 0.75	Sand Rock	Cherokee, AL	DIME TO PENNY SIZE HAIL FELL NEAR SAND ROCK.
22:03 UTC	HAIL 0.88	6 Ne Sand Rock	Cherokee, AL	NICKEL SIZE HAIL REPORTED AT THE INTERSECTION OF COUNTY ROAD 43 AND 275.
22:10 UTC	TSTM WND DMG	Sand Rock	Cherokee, AL	TREES REPORTED DOWN IN SAND ROCK.
22:15 UTC	TSTM WND DMG	2 Sse Horton	Marshall, AL	A ROOF WAS BLOWN OFF A CHICKEN HOUSE IN THE MOUNT HEBRON COMMUNITY.
22:15 UTC	TSTM WND DMG	Douglas	Marshall, AL	TREES DOWN ALONG AL HWY 75 IN THE DOUGLAS CITY LIMITS.
22:16 UTC	HAIL 0.5	Centre	Cherokee, AL	DIME SIZE HAIL REPORTED IN CENTRE.
22:24 UTC	TSTM WND DMG	1 E Strawberry	Blount, AL	TREES DOWN AND ROOF BLOWN OFF HOUSE ON HOPEWELL ROAD IN NORTH BLOUNT COUNTY.
22:30 UTC	TSTM WND DMG	2 Nnw Mountainboro	Etowah, AL	SEVERAL TREES DOWN, PEA SIZED HAIL, AND POSSIBLE FUNNEL CLOUD IN THE NEW UNION COMMUNITY.
22:33 UTC	HAIL 0.75	3 Se Ellisville	Cherokee, AL	DIME TO PENNY SIZE HAIL WAS OBSERVED IN SOUTHERN CHEROKEE COUNTY SOUTHEAST OF ELLISVILLE.
22:37 UTC	HAIL 0.75	Reece City	Etowah, AL	DIME SIZED HAIL REPORTED IN REECE CITY.
22:41 UTC	TSTM WND DMG	3 Ne Snead	Blount, AL	TREE DOWN ON HIGHWAY 75 BETWEEN SNEAD AND DOUGLAS.
22:41 UTC	HAIL 1	Leesburg	Cherokee, AL	QUARTER SIZED HAIL REPORTED IN LEESBURG.
22:45 UTC	TSTM WND DMG	7 Nne Wilsonia	Etowah, AL	ROAD COVERED WITH DEBRIS AND 2 TREES DOWN ON TABOR ROAD BETWEEN SCROUNGEOUT AND BLACK CREEK.
22:52 UTC	HAIL 0.75	1 N Gadsden	Etowah, AL	PENNY SIZED HAIL REPORTED ON NOCCALULA MOUNTAIN.
23:09 UTC	LIGHTNING	4 S Centre	Cherokee, AL	HORSE KILLED BY LIGHTNING STRIKE IN THE BLAIRTOWN COMMUNITY.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

This ground now

The live radar over the track Every 2008 tornado in Alabama Every tornado in Alabama since 1950 Warnings in force in Alabama now The forecast where you are

The other tornadoes of May 20, 2008

5 more were confirmed in the United States that day.

Date	Time	Rating	Where	Path (mi)	Width (yd)	Injuries	Damage
May 20	5:07 PM EDT	EF1	Bamberg, SC	13.3	800
May 20	6:20 PM EDT	EF0	Washington, GA	1.0	50		$2,000
May 20	6:35 PM EDT	EF1	Cherokee, GA	5.9	1,760	4	$46 million
May 20	7:41 PM EDT	EF0	Burke, GA	10.4	600		$56,000
May 20	9:00 PM EDT	EF1	Hancock, GA	4.8	125		$76,000

What this means

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

Sources

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.